From: Rick DeNatale <rick.denatale@...>
Date: 2007-12-18T01:05:37+09:00
Subject: Re: Backslashes in Command Line Arguments

On 12/16/07, Joseph Pecoraro <joepeck02@gmail.com> wrote:
> In writing a script that takes strings on the command line I have run
> into a small problem which I don't see any way around.  Here is a very
> simplified program that just prints out the first command line argument,
> and using p you can see exactly what is in the string.
>
> [example.rb]
> <code>p $*[0]</code>
>
>
> Now when I send some different (but similar) strings I end up with the
> same result in the ARGV array:
>
> $ ruby example.rb "\a"
> "\\a"
>
> $ ruby example.rb "\\a"
> "\\a"
>
> $ ruby example.rb \\\a
> "\\a"
>
> 1) Is this because I am running in bash and the shell maps the \\ into a
> single backslash?

No, it's because you are using p instead of puts.

The p method prints the result of sending the inspect message to its
argument, and String#inspect produces a what ruby string literal to
represent the string looks like, and since \ is the escape character
in ruby string literals it needs to be escaped itself in the  output
of inspect.

-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/